Cholesterol is a waxy substance necessary for all living tissue. The body manufactures most of the cholesterol it needs. Additional cholesterol is taken in from certain foods we eat.

Too much cholesterol in the blood is not healthy because it can build up in the walls of arteries, causing the blood vessels to narrow (atherosclerosis). Narrowed blood vessels carry less blood and may increase a person's risk for a stroke or heart attack.

Lowering cholesterol levels in the blood makes good sense, especially for people who are at risk for a transient ischemic attack (TIA) or stroke. Diet changes and, if necessary, drugs can be used to keep blood cholesterol at an acceptable level.

Treatment with cholesterol-lowering drugs called statins can slow the development of atherosclerosis in the carotid arteries for some people and may reduce the chance of having a TIA or stroke, especially for people who have a history of coronary artery disease. For more information, see the topic High Cholesterol.